Many sports are based on the development of athletic abilities such as specialized skills, fast responses, speed, excellent coordination and enhanced muscular strength. Athletes commonly strive to reach their potential in their sport but there are many sports wherein it is difficult to quantify or objectively measure an athlete's ability with regards to certain aspects of a specific sport. As a result of this difficulty, an athlete's performance in sports, such as, for example, karate, tennis or soccer is usually determined through a coach's observation or by competing against other athletes. Objective measurement of athletic ability is particularly beneficial for training since this provides the athlete with a means to identify those abilities and skills which require special attention and to measure improved performance. The use of a device which objectively measures an athlete's performance or skill can greatly assist athletes in reaching their potential and in deriving pleasure and satisfaction from participation in their chosen sport.
Karate is a martial arts sport which simulates certain types of unarmed combat. A karate athlete kicks or strikes with hands, arms, feet or legs while moving the whole body. The athlete may aim kicks or strikes at a target such as a punching bag or an opponent. Many karate training exercises and competitive contests involve movements designed to hit an imaginary opponent, i.e. the athlete executes hitting and striking movements without actually hitting a target. Some of the karate movements and techniques are executed in a prearranged sequence or pattern commonly referred to as a form.
Various devices have been developed for measuring skills and performance for martial arts and other combat related sports such as boxing. Typically, these devices measure the athlete's response time or the force exerted when hitting a target. See, for example U.S. Pat. No. 4,974,833 (Hartman et al. 1990) which discloses an electronic martial arts training device having illuminated target areas. The target sensor consists of a load speaker cone. Hartman et al. teach that hitting the load speaker cone induces an electric signal which is proportional to the force with which the target is struck. The '833 apparatus utilizes timed sequences to test the athlete's response time. U.S. Pat. No. 4,941,660 (Winn et al., 1990) discloses a computer interfaced device to determine the force with which a punching bag is hit by an athlete. The '660 punching bag comprises a water filled bladder having a pressure transducer. The transducer is coupled to a pressure indicator which is interfaced with a computer. Winn et al. teach that the apparatus disclosed in '660 enables the athlete to measure the force which is applied by striking or kicking the bag and the time which is elapsed between punches.
U.S. Pat. No. 4,883,271 (French, 1989) discloses sport impact measuring apparatus comprising a deformable container having a piezoelectric transducer strip attached to the outside surface. Hitting the container causes the container surface to be deformed resulting in a dimensional change in the piezoelectric strip. French teaches that the deformation of the piezoelectric strip causes the strip to generate an electrical potential which is proportional to the force which is applied by hitting the container. The '271 patent also contemplates the use of a strain gauge on a flexible container as an alternate embodiment. U.S. Pat. No. 4,818,234 (Redington et al., 1989) discloses a psychophysiological reflex arc training simulator having a target area which includes a sensor comprising a pressure transducer, such as, for example, a strain gauge. Redington et al. teach that the sensor creates a measurable electrical change which is proportional to the impact force of a hit upon the target rendering the device capable of measuring the athlete's response time between the activation prompt of the test cycle and hitting the target sensor.
U.S. Pat. No. 4,763,284 (Carlin, 1988) discloses a reaction time and force feedback system using a force sensor incorporated in a housing attached to one of the athlete's limbs or attached to a pad worn by an athlete. The sensor consisting of a strain gauge is preferably oriented on the limb in close proximity to an internal bone structure in order to maximize the detection of the forces. Carlin teaches that the apparatus is capable of measuring force magnitude and elapsed time between hits. U.S. Pat. No. 4,627,620 (Yang, 1986) discloses an electronic athlete trainer for improving skills in reflex, speed and accuracy wherein the apparatus can select targets in a random sequence and-determine the elapsed time for hitting the selected targets. The target comprises a reset switch wherein a normally closed contact is opened as a result of a hit. U.S. Pat. No. 4,534,557 (Bigelow et al., 1985) discloses a reaction time and applied force feedback sports training system wherein a strain gauge sensor is used to sense the force which is applied to a target by, for example, by hitting the target. The strain gauge comprises compression sensors and tension sensors. The athlete's reaction time is measured. Bigelow et al. teach that the device can be used by several athletes simultaneously, each hitting selected targets.
The above referenced U.S. patents attempt to measure the force with which a martial arts target or related target is hit by a user, such as an athlete, and/or the athlete's response time in hitting the target. Sensors utilized in these devices include load speaker cones, pressure transducers, compression sensors, tension sensors and strain gauges. A common shortcoming of these types of sensors is the inability to measure movement resulting from the absorption of kinetic energy which results from a hitting or kicking movement. None of the above prior art sensors is believed operable for measuring an athlete's kicking or punching movements when the athlete purposely executes a movement without hitting a target, or purposely hitting the target very lightly in order to avoid injury or discomfort.
Accordingly, the need exists for a device and method to objectively determine performance in martial arts, boxing and other simulated combat sports wherein the user, such as an athlete, does not contact a target or contacts a target very lightly.
In ball sports, such as, for example, soccer the athlete contacts the ball with the foot, leg or head in order to move the ball in a certain direction while controlling ball speed and spin. In football, the ball is kicked for example when punting or when attempting to score a field goal.
Bigelow et al. '557 teach that a conventional football can be adapted to contain a pressure transducer to sense the applied force when the ball is kicked. It is well known to those skilled in the art that the playing characteristics of a ball used in, for example, soccer or football are greatly affected by the attachment of an external device thus making the '557 device undesirable for evaluating the athlete's performance.
Carlin '284 teaches a strain gauge sensor attached to a limb for measuring force exerted by that limb. It is well known to those skilled in the art that kicking a ball involves transmitting the foot's kinetic energy to the ball. Carlin stresses the importance of placing the sensor in close proximity to the shin bone. However, it is thought that the complex movements which are involved in kicking a ball involve flexing the ankle as the kick is executed. Consequently, strain gauge measurements of the force exerted by the leg or foot bones are undesirable for measuring ball kicking performance.
Accordingly, the need exists for a device and method for determining ball kicking performance by measuring the kinetic impact exerted by the foot on the ball in a manner which takes into account the flexing of the ankle during kicking.
In tennis, the player attempts to hit a ball with a racket over a net into the opponent's court. This sport requires power and accuracy in hitting the ball. Players use different techniques to hit the ball in order to achieve a desired special effect, such as, for example, giving the ball a spin motion as well as a forward motion. Similarly, power and accuracy are needed in baseball where a ball is hit with a bat. In sports such as tennis and baseball, the athlete's contact with the ball is indirect since the ball is moved by a racket or a bat rather than by direct contact with the athlete.
U.S. Pat. No. 1,170,467 (Taylor, 1916) discloses a baseball training apparatus using a ball equipped with a sensor for sensing air compression when the ball is struck with a bat. The Taylor device is undesirable for measuring baseball hitting performance since the sensor ball is not a typical baseball because it is mounted on a plunger. Also the device is thought to be poorly suited for testing under playing conditions since the sensor makes the ball unsuitable for the ball pitching techniques which are typical of baseball.
Accordingly, the need exists for a device and method which enables the user, such as an athlete, to determine ball hitting performance in sports such as baseball and tennis wherein the athlete hits a ball by means of a racket, bat or stick such as a hockey stick.